Letter to Sir Archibald Geikie from Capt Clarence Edward Dutton, thanking him for his articles on weathering and postulating that the Grand Canyon was formed in this manner, and that he is preparing a section concerning this for Geikie's manual. He recommends William Henry Holmes' topographical drawings of the Grand Canyon and reports that photolithographs are being prepared. He gives details of the depths of the individual geological stratifications which can be observed at the Grand Canyon. He recommends the monograph Report on the Geology of the Henry Mountains, ( 1877) by Grove Karl Gilbert which lays out the principles of erosion. He encloses a report by Clarence King and reports on the position regarding the current Congress debate concerning the expansion of the United States Geological Survey to incorporate individual State Surveys. He reports that he hopes to do field work to the South of the Grand Canyon and the Kaibab region over the summer, and invites Geikie to accompany him.